peter teaching derek to control the shift via anger really did fuck him for years huh

i'll come back and finish this later, preferably after doing a closer rewatch of tw but cliffnotes version is that when derek loses his powers in s4, i think part of it has to do with the fact he connected back to his 'origins' which is literally him right before peter teaches him how to use anger to control the shift, and that brief connection to his younger, less traumatized self kinda loosened that bit of anger he's kept inside him all this time.

also derek's hair-trigger temper in s1 - which admittedly has more to do with trauma and paranoia-induced hyper-vigilance (ooh wait s1!derek/s5!stiles comparison-) makes even more sense if you consider that he's been connecting to his anger and using it as a control since he was in high school